2.5 Outcomes
The primary outcome of interest was the composite of the any of the following medical resource uses during the follow-up-period: hospitalization of all-causes, laboratory/radiological services, and systemic antibiotics use. These outcome events were identified by claims records for procedures and medications. For laboratory services, any of the complete blood count, chemical panel or rapid antigen tests were assessed. Radiological examination represented plain radiography regardless of sites. As secondary outcomes, each component of the primary outcomes and return visit to medical institutions within 9 days were compared between the baloxavir and NAIs groups. These outcomes were prespecified prior to data analysis.